Sarcoid-Like Reactions

1.1 History and prevalance According to a revised definition introduced by the International Conference on Sarcoidosis in 1975, sarcoidosis is a multisystem granulomatous disorder of unknown etiology, most often affecting young adults, in which patients present with hilar lymphadenopathy, pulmonary infiltration, and skin or eye lesions. This definition has been the most accepted till date, although many advancements have been made to understand the pathogenesis of this disease. Sarcoidosis is a chronic granulomatous disease, which is characterized by the formation of non-caseating granulomas at multiple sites. It is a systemic disorder of unknown etiology, although multiple factors like mycobacterium, viruses like mumps and influenza, beryllium, zirconium, genetic predisposition, autoimmune diseases and also carcinomas, are considered to be responsible for its etiology. In the first described case of sarcoidosis 120 years ago, it was called "livid papillary psoriasis" by Jonathan Hutchinson. Hutchinson suspected that this was a variant of mumps. The patient presented with purplish skin lesions and gout and later died of renal failure. Sarcoidosis has been reported to occur in association with malignant tumours, either preceeding or following malignancy. In 1977, a study was conducted on 580 cases of sarcoidosis. Out of these, 7 cases were found to be associated with malignancy. But these authors considered that the association of sarcoidosis to malignant tumour, would be just a co-incidence. (Battesti JP et al., 1977) By 1987, 23 cases of malignancy following sarcoidosis were reported. It was observed that lung and breast cancer may occur more often than other tumours after sarcoidosis. It was considered that the immunologic abnormalities associated with sarcoidosis may promote the development of certain malignant tumors. (Brincker H, 1987). Patients may rarely present with typical sarcoidosis occurring before, during or after the diagnosis of cancer. Recent studies have documented this type of cases, particularly with lymphomas, testicular and lung cancers, melanomas and hepatocarcinomas. As far as lung cancer is considered, coexistence of sarcoidosis and lung cancer in the same patient is not common, and only 29 such cases have been reported. If bilateral mediastinal lymphadenopathy is found in a case of lung cancer associated with sarcoidosis, surgical tumor resection should be considered. It has been reported that in patients with malignant diseases, non-caseating epithelioid cell granulomas are occasionally found in lymph nodes draining a region containing the malignant tumor. These non-caseating granulomas are present at single or multiple organ